ALCOA SPECIALTY ALLOYS: SupraCast™

SupraCast Alloys Castability, good thermal conductivity, high tensile strength and fatigue resistance at both low and high temperatures.

• C3A1: Suitable for applications such as cylinder heads, connecting rods, turbo chargers, brake calipers, and impellers.

• C677F: Designed for high-pressure die cast (HPDC) components that require high strength and fatigue performance at elevated temperatures (150o C to 300o C).

Superior alloy for high performance power train applicationsOver a decade of research with Alcoa’s Technical Center scientists culminated in an alloy solution suitable for components exposed to the elevated temperatures in high performance engines.

The art is in the science behind superior performance at elevated temperatures

SupraCast™ C3A1 Technical Data

SupraCast™ C677F Technical Data

SupraCast Alloys are optimized to meet the challenging future power train requirements by eliminating conventional aluminum alloy barriers.

• Controlling the formation of the ‘Q’ phase by maintaining copper and magnesium at appropriate levels in the alloy.

• Using a solution heat treatment schedule based on thermodynamic calculations of the solidus temperature in the multi-component alloy system.

• Employing micro-alloying additions for optimal high temperature strength and creep resistance.

Si Fe Cu Mn Mg V Zr Ti Others Each

Others Total

8 - 1.35 0.08 0.25 - - - - -

10 0.2 2.1 0.6 0.55 0.3 0.3 0.2 0.05 0.15

Si Fe Cu Mn Mg V Zr Ti Others Each

Others Total

8 - 0.7 0.35 0.2 0.08 0.08 - - -

10 0.5 2 0.8 0.55 0.3 0.3 0.2 0.05 0.15

AlloyTYE at Room Temperature TYE at 300°C**

Fatigue Strength, (MPa) (R-1, 107 Cycles)

Yield Strength (MPa)

UTS (MPa)

Elongation (%)

Yield Strength (MPa)

UTS (MPa)

Elongation (%) 150oC 250oC

C3A1– T6 280-350 370-400 2-3 55 75 41 95 79

A356-T6 220 280 7 25 35 45 57

AlloyYield Strength (MPa)

UTS (MPa) Elongation (%)

Fatigue Strength, (MPa) (R-1, 107 Cycles)

RT 150°C

C677F-T5 210-240 280-300 2-3 90 80

A380 160 240 2 57 50

Density (g/cm3)

Young’s Modulus (GPa)

Coeff. Of Thermal Expansion (CTE) 20-300°C (mm/m/K)

Thermal Conductivity [W/(mK)]

Electrical Conductivity (%IACS)

Solidification Range (°C)

2.70 72-74 20.6-28.6 140-160 32-36 595-510

Density (g/cm3)

Young’s Modulus (GPa)

Coeff. Of Thermal Expansion (CTE) 20-300°C (mm/m/K)

Thermal Conductivity [W/(mK)]

Electrical Conductivity (%IACS)

Solidification Range (°C)

2.69 71-73 20.6-28.6 140-160 32-36 600-510

CHEMICAL COMPOSITION CHEMICAL COMPOSITION (all in wt%. Single values indicate maximum content) (all in wt%. Single values indicate maximum content)

MECHANICAL PROPERTIES* MECHANICAL PROPERTIES*

PHYSICAL PROPERTIES (TYPICAL VALUES) PHYSICAL PROPERTIES (TYPICAL VALUES)

OTHER PROPERTIES OTHER PROPERTIES

* The achievable mechanical properties are strongly dependent on the casting process used. The table refers typical properties obtained in semi-permanent mold casting.

** Strengths were measured after 500 hours exposure at temperature.

* The achievable mechanical properties are strongly dependent on the casting process used. The table refers typical properties obtained in high-pressure die casting (HPDC).

• Castability: Very good, suitable for sand casting, investment and permanent mold casting

• Machinability: Very good• Weldability: Good• Corrosion Resistance (ASTM G110): Similar corrosion resistance as A359

alloy (the additions of Cu do not change the corrosion mode nor increase the depth of attack of the alloys).

• Castability: Very good • Machinability: Very good• Weldability: Good• Corrosion Resistance: Similar corrosion resistance as A359 alloy